<template>
  <transition name="el-fade-in-linear el-fade-in">
    <div class="markdown-preview-wrapper" v-show="visible"
      @click.self="closeMarkdownPreview">
      <!-- 顶部信息栏 & 工具栏 -->
      <div class="tip-wrapper" v-if="visible">
        <div class="name" :title="$file.getFileNameComplete(fileInfo)">
          {{ $file.getFileNameComplete(fileInfo) }}
          <span class="un-save" v-show="isModify">（未保存）</span>
        </div>
        <div class="editor-preveiw">
          在线预览{{ editable ? ' & 编辑' : '' }}
        </div>
        <div class="tool-wrapper">

          <el-tooltip effect="dark" placement="bottom">
            <div slot="content">
              1. 点击文档以外的区域可退出查看<br />
              2. 按 Esc 键可退出查看
            </div>
            <div class="item text-wrapper">
              <span class="text">操作提示</span>
              <i class="el-icon-s-opportunity"></i>
            </div>
          </el-tooltip>
          <i class="item el-icon-close" title="关闭预览"
            @click="closeMarkdownPreview"></i>
        </div>
      </div>
      <!-- mavon-editor 组件，配置项说明文档 https://www.npmjs.com/package/mavon-editor -->
      <mavonEditor ref="mavonEditor" v-model="markdownText" :toolbars="toolbars"
        :editable="editable" :toolbarsFlag="toolbarsFlag"
        :externalLink="externalLink" :subfield="screenWidth > 768 ? true : false"
        defaultOpen="preview" v-loading="markdownLoading"
        @save="handleModifyFileContent"></mavonEditor>
    </div>
  </transition>
</template>

<script>
import { mavonEditor } from 'mavon-editor'
import 'mavon-editor/dist/css/index.css'
// 代码高亮样式表
import '_public/mavonEditor/css/tomorrow-night.css'
import '_public/mavonEditor/css/github-markdown.css'
import store from '@/store/index.js'
import { getFilePreview, modifyFileContent } from '_r/file.js'

export default {
  name: 'ImgPreview',
  components: {
    mavonEditor
  },
  data() {
    return {
      visible: false, //  markdown 预览遮罩层组件是否显示
      originalMarkdownText: '', //  markdown 原本的文本
      markdownText: '', //  markdown 实时修改的文本
      markdownLoading: false, //  markdown 内容是否加载中
      // 工具栏
      toolbars: {
        bold: true, // 粗体
        italic: true, // 斜体
        header: true, // 标题
        underline: true, // 下划线
        strikethrough: true, // 中划线
        mark: true, // 标记
        superscript: true, // 上角标
        subscript: true, // 下角标
        quote: true, // 引用
        ol: true, // 有序列表
        ul: true, // 无序列表
        link: true, // 链接
        imagelink: true, // 图片链接
        code: true, // code
        table: true, // 表格
        fullscreen: true, // 全屏编辑
        readmodel: true, // 沉浸式阅读
        htmlcode: true, // 展示html源码
        help: true, // 帮助
        /* 1.3.5 */
        undo: true, // 上一步
        redo: true, // 下一步
        trash: true, // 清空
        save: true, // 保存（触发 events 中的 save 事件）
        /* 1.4.2 */
        navigation: true, // 导航目录
        /* 2.1.8 */
        alignleft: true, // 左对齐
        aligncenter: true, // 居中
        alignright: true, // 右对齐
        /* 2.2.1 */
        subfield: true, // 单双栏模式
        preview: true // 预览
      }
    }
  },
  computed: {
    // 屏幕宽度
    screenWidth() {
      return store.state.common.screenWidth
    },
    // 是否修改
    isModify() {
      return this.originalMarkdownText !== this.markdownText
    },
    // 外链 cdn 改为本地引入
    externalLink() {
      let context =
        process.env.NODE_ENV === 'production'
          ? '/' //  生产环境
          : '/' //  开发环境
      return {
        markdown_css: function () {
          // 这是你的markdown css文件路径
          return `${context}mavonEditor/css/github-markdown.css`
        },
        hljs_js: function () {
          // 这是你的hljs文件路径
          return `${context}mavonEditor/js/highlight.min.js`
        },
        hljs_css: function () {
          // 这是你的代码高亮配色文件路径
          return `${context}mavonEditor/css/tomorrow-night.css`
        },
        hljs_lang: function () {
          // 这是你的代码高亮语言解析路径
          return `${context}mavonEditor/js/lang.hljs.js`
        },
        katex_css: function () {
          // 这是你的katex配色方案路径路径
          return `${context}mavonEditor/css/katex.min.css`
        },
        katex_js: function () {
          // 这是你的katex.js路径
          return `${context}mavonEditor/js/katex.min.js`
        }
      }
    },
    // 工具栏是否展示
    toolbarsFlag() {
      return this.editable
    }
  },
  watch: {
    // 监听 markdown 查看组件 显隐状态变化
    visible(val) {
      if (val) {
        this.getMarkdownText()
        // 添加键盘 Esc 事件
        this.$nextTick(() => {
          document.addEventListener('keyup', (e) => {
            if (e.keyCode === 27) {
              this.closeMarkdownPreview()
            }
          })
        })
      } else {
        document.removeEventListener('keyup', (e) => {
          if (e.keyCode === 27) {
            this.closeMarkdownPreview()
          }
        })
      }
    }
  },
  methods: {
    /**
     * 获取 markdown 文本内容
     */
    getMarkdownText() {
      this.markdownLoading = true
      getFilePreview({
        userFileId: this.fileInfo.userFileId,
        extendName: this.fileInfo.extendName,
        filePath: this.fileInfo.filePath
      }).then((res) => {
        this.markdownLoading = false
        this.originalMarkdownText = res
        this.markdownText = res
      })
    },
    /**
     * 修改 markdown 文本内容
     */
    handleModifyFileContent() {
      this.markdownLoading = true
      modifyFileContent({
        userFileId: this.fileInfo.userFileId,
        fileContent: this.markdownText
      })
        .then((res) => {
          this.markdownLoading = false
          if (res.success) {
            this.$message.success('已保存')
            this.getMarkdownText()
          } else {
            this.$message.error(res.message)
          }
        })
        .catch((err) => {
          this.markdownLoading = false
          this.$message.error(err.message)
        })
    },
    /**
     * 关闭 markdown 预览
     */
    closeMarkdownPreview() {
      this.visible = false
      this.callback('cancel')
    }
  }
}
</script>

<style lang="stylus" scoped>
@import '~_a/styles/varibles.styl';

.markdown-preview-wrapper {
  position: fixed;
  top: 0;
  right: 0;
  bottom: 0;
  left: 0;
  overflow: auto;
  width: 100%;
  height: 100vh;
  z-index: 2;
  text-align: center;
  display: flex;
  align-items: center;
  animation: imgPreviewAnimation 0.3s;
  -webkit-animation: imgPreviewAnimation 0.3s; /* Safari and Chrome */
  animation-iteration-count: 0.3;
  -webkit-animation-iteration-count: 0.3;
  animation-fill-mode: forwards;
  -webkit-animation-fill-mode: forwards; /* Safari 和 Chrome */
  @keyframes imgPreviewAnimation {
    0% {
      background: transparent;
    }
    100% {
      background: rgba(0, 0, 0, 0.8);
    }
  }
  @keyframes imgPreviewAnimation {
    0% {
      background: transparent;
    }
    100% {
      background: rgba(0, 0, 0, 0.8);
    }
  }
  .tip-wrapper {
    position: fixed;
    top: 0;
    left: 0;
    z-index: 2;
    background: rgba(0, 0, 0, 0.5);
    padding: 0 48px;
    width: 100%;
    height: 48px;
    line-height: 48px;
    color: #fff;
    font-size: 16px;
    display: flex;
    justify-content: space-between;
    .name {
      flex: 1;
      padding-right: 16px;
      text-align: left;
      overflow: hidden;
      text-overflow: ellipsis;
      white-space: nowrap;
      .un-save {
        color: $Warning;
        font-size: 14px;
      }
    }
    .tool-wrapper {
      flex: 1;
      display: flex;
      justify-content: flex-end;
      .item {
        margin-left: 16px;
        height: 48px;
        line-height: 48px;
        cursor: pointer;
        &:hover {
          opacity: 0.7;
        }
      }
      .save-img {
        margin: 16px 0;
        width: 16px;
        height: 16px;
      }
      .download-link {
        color: inherit;
        font-size: 18px;
      }
      .text-wrapper {
        .text {
          margin-right: 8px;
        }
      }
    }
  }

  >>> .v-note-wrapper {
		box-shadow: none !important;
		border: 1px solid $BorderBase;
		.v-note-op {
			border-bottom-color: $BorderBase;
      .op-image {
        .dropdown-item:nth-of-type(2) {
          display: none;
        }
      }
		}
		.v-note-navigation-wrapper {
			.v-note-navigation-content {
				h1,
				h2,
				h3,
				h4,
				h5,
				h6 {
					color: $PrimaryText;
					&:hover {
						color: $PrimaryText;
					}
				}
			}
		}
	}
	>>> .v-note-wrapper:not(.fullscreen) {
    margin: 56px auto 0 auto;
    width: 90vw;
		height: calc(100vh - 80px);
	}
}
</style>
